Biological Sciences
Plant Vector
A plant vector is a tool used in genetic engineering to introduce foreign genes into plant cells. It is typically a small, circular DNA molecule that can replicate independently within the plant cell. Plant vectors often contain genetic elements such as promoters and selectable markers to facilitate the expression and identification of the introduced genes.
Written by Perlego with AI-assistance
Related key terms
1 of 5
10 Key excerpts on "Plant Vector"
eBook - PDF- Indra Vasil(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
CHAPTER 4 Plant Gene Vectors and Genetic Transformation: Plant Viruses as Vectors Bruno Gronenborn Volker Matzeit Max-Planck-Institut fur Zuchtungsforschung Abteilung Genetische Grundlagen der Pflanzenzuchtung Koln, Federal Republic of Germany I. Introduction 69 II. CaMV and Its Development into a Plant Vector 70 A. The Organization of the CaMV Genome 72 B. The Replication of CaMV 75 C Homology between CaMV and Retroid Elements 77 D. Mutants of CaMV 77 E. Translational Polarity 79 F. Vector Variants of CaMV 80 G. Defective Complementing Mutants of CaMV 81 III. CaMV as a Tool in Plant Genetic Engineering 82 IV. Geminiviruses 83 A. Wheat Dwarf Virus 85 V. Vectors Based on RNA Plant Viruses 89 VI. Conclusion and Outlook 90 References 91 I. INTRODUCTION Viral vectors have been invaluable for the analysis of genome structure and the elucidation of gene functions in pro- and eukaryotes. Our cur-rent knowledge of molecular biology, as well as the progress in genetic C E L L C U L T U R E AND SOMATIC C E L L G E N E T I C S O F P L A N T S , VOL. 6 69 Copyright © 1989 by Academic Press, Inc. All rights of reproduction in any form reserved. 70 Bruno Gronenborn and Volker Matzeit engineering has been helped substantially by the study of bacterial vi-ruses such as bacteriophage λ or phage M13 (Hendrix et al, 1983; Ptashne, 1986). In higher eukaryotes like birds and mammals, retroviruses, papovavi-ruses (e.g., SV40 and BPV), and adenoviruses were used as classical paradigms for the study of the primary structure of genes and of their regulation. Based on these viruses, a large variety of vectors has been developed to transfer and study genes within their natural or in alien environments. Furthermore, the methods for transfection and transfor-mation of single cells and for the generation of transgenic animals were predominantly developed relying on viral vectors or viral control ele-ments (Rigby, 1983; Cepko et al, 1984; van der Putten et al, 1985).
eBook - PDF- Indrachand Chavan(Author)
- 2023(Publication Date)
- Delve Publishing(Publisher)
2.12.4. Plant Virus Vectors Viruses are obligatory intracellular parasites that replicate via the molecular machinery of a specific host. Viruses have not been discovered infecting plants via transmission vectors like aphids, insects, nematodes, & fungi. These modified viruses are employed as alternate sources for plant transformation; typical plant viruses used in transgenic plant production include Cauliflower mosaic virus (CaMV), Tobacco mosaic virus (TMV), Alfafa mosaic virus (AMV), Potato virus X (PVX), & Cowpea mosaic virus (CPMV). In two ways, the wild-type plant viral vectors have been enhanced and modified to allow their employment with Agrobacteria and the plant host for greater efficiency. The first approach would be to create virus vectors that are similar to wild types that carry the desired gene and are capable of infecting plants. The second strategy would be to create a ‘deconstruct’ virus, which involves removing unwanted viral genes, such as the coat protein- expressing gene, and replacing them with useful genes, like reporter genes or theantibiotic resistance genes, to allow the transgenic screening. Transgenic Plants: Gene Constructs, Vector and Transformation Method 51 Figure 2.6. Symptoms of Alfalfa Mosaic Virus on potato leaves. Source: Image by Wikimedia Commons 2.13. TRANSFORMATION TECHNIQUES FOR THE PRODUCTION OF TRANSGENIC PLANTS Plant transformation is the process of changing the genetic contents of an interesting plant by inserting DNA segments into the plant genome to reach optimal gene expression. A wide range of plant transformation techniques are now available to the general population. These plant transformation approaches are classified as either indirect or direct gene transfer.
eBook - ePub- Günter Kahl, Josef S. Schell(Authors)
- 2014(Publication Date)
- Academic Press(Publisher)
Chapter 21 in this treatise), is of course not the only way DNA can be introduced into a plant. An alternative is the infection of plants with plant viruses. Only relatively recently has the potential of plant viral DNA as prospective Plant Vector been recognized.The combination of several properties can turn a piece of DNA into a Plant Vector: (1) its DNA should be available in useful quantities (i.e., it should be molecularly cloned), (2) its maintenance in a plant cell and/or plant should be easily, ideally selectively recognized, (3) it should not be pathogenic, (4) it should be able to accept the genetic information to be transferred into the plant, and (5) if heritable changes of the transformed plant are desired, the vector or a derivative thereof should be stabily maintained in the new host. Furthermore, at one stage or another the transformed plant cell has to be purified by cloning and regenerated into a plant. This cell cloning will most likely have to be performed starting from the protoplast stage, since viral DNA or derivatives thereof will have to be introduced into the cell wall-free plant cells. In contrast to the Ti plasmid system, a transformation system has to be established consisting of plant protoplasts and plant viral DNA (naked, precipitated, or somehow coated). This system is thus an artificial one, in contrast to the in vivo Agrobacterium –plant DNA transfer. This possible disadvantage and technical inconvenience is matched by easier handling and engineering of the virus DNA relative to Ti DNA, as a result of the enormous difference in size.There are other important properties that justify research on plant viruses as potential vectors: many copies of the plant virus are maintained in the infected cell, which may be exploited for overproduction of an interesting function. However, stable maintenance via integration into the host DNA has not been demonstrated (see below).
eBook - PDFPlant Biotechnology
Biotechnology
- Shain-dow Kung, Charles J. Arntzen(Authors)
- 2014(Publication Date)
- Butterworth-Heinemann(Publisher)
PART I Basic Techniques in Plant Biotechnology This page intentionally left blank CHAPTER 1 Vectors for Gene Transfer in Higher Plants Frank F. White Progress in the development of plant gene transfer vectors can be attributed to developments in genetic and recombinant DNA techniques, plant tissue culture techniques and the design of selection methods for transgenic plant cells or tissue. In terms of vector development and use, the greatest progress has involved the Agrobacterium system. Although this chapter emphasizes the Agrobacterium system of DNA transfer, methods of direct DNA transfer are well developed and in many important circumstances are the clearest choice for achieving gene transfer. Viral vectors also present interesting possibilities for plant transformation and may have advantages in certain applications. This chapter will not delve into the development of plant cell manipu-lation and regeneration methods. However, progress in plant cell transfor-mation, particularly by direct DNA transfer methods, has been largely dictated by cell culture techniques. Thus, one of the critical factors in the transformation of a particular plant species is the ability to manipulate and regenerate whole plants from expiants or protoplasts. Fortunately, many important crop species are amenable to plant regeneration. On the other The work was supported by a research grant, RF84066, Allocation No. 3, from the Rockefeller Foundation. _ 4 Vectors for Gene Transfer in Higher Plants hand, other important crop species—notably soybeans, corn, and wheat— have been more recalcitrant toward regeneration schemes. In general, the ability to introduce DNA into the genomes of these species is not the limiting factor. Stable gene transfer has been demonstrated in most cases, and progress in genetic engineering depends on developments in techniques for inducing tissue differentiation.
eBook - ePubGenetically Engineered Viruses
Development and Applications
- Dr Eddie Blair, Dr Chris J A Ring(Authors)
- 2023(Publication Date)
- Garland Science(Publisher)
Chapter 4 Plant viruses Christophe Lacomme, Greg P. Pogue, T. Michael A. Wilson and Simon Santa Cruz4.1 Introduction
Progress in the understanding of plant virus gene regulation has provided a diverse collection of tools that are routinely exploited in both basic and applied plant molecular biology. Regulatory elements have been derived from both RNA and DNA plant viruses that have found widespread application in transgenic plant technology (Mushegian and Shepherd, 1995). For example the cauliflower mosaic virus (CaMV) 35S promoter and the tobacco mosaic virus (TMV) Ω translational enhancer are routinely used to direct and regulate transgene expression. In addition to their utility as ‘toolboxes’ in providing sequences of value in plant genetic engineering plant viruses also offer the possibility of providing convenient and readily manipulated vectors for the rapid and high-level expression of foreign genes in plants. To date the most widespread application of plant virus-based vectors has been in the area of basic research and less attention has focused on the potential of virus-based vectors in commercial biotechnology. In part the emphasis on viral vectors as research tools reflects the successes achieved in the development of stable transformation technologies for plants. Techniques for Agrobacterium-mediated transformation and more recently biolistic introduction of foreign genes that are effective in a wide range of agronomically important species have been developed over the last 15 years. The products of these novel molecular breeding technologies are now commercially available and include agronomically valuable traits, such as herbicide tolerance, disease resistance and pest resistance (Birch, 1997 ). In addition to agronomic improvement transgenic plants also have the potential for exploitation as bioreactors for the bulk production of desirable proteins (for reviews see:Fischer et al., 1999a; 1999b; Porta and Lomonossoff, 1996
- R C Ray, O.P. Ward(Authors)
- 2008(Publication Date)
- CRC Press(Publisher)
The strategies that have been tested for foreign gene expression in various virus-based vectors include gene replacement, gene insertion, epitope presentation, use of virus controlled gene expression cassettes, and complementation. Virus vectors are being utilized for foreign gene expression in fundamental research and biotechnology applications (Scholthof et al., 1996). E E Q MICROBIAL BIOTECHNOLOGY IN HORTICULTURE—VOL 2 Researchers are working on the development of new viral vectors (Gleba et al, 2004) that are not simply carbon copies of wild type viruses carrying heterologous coding sequences. Instead, new vectors are being designed to function as integrated expression systems, with transgenic host plants pre-engineered to provide some of the functions that are normally provided by the vector. Such integrated systems are expected to provide a more efficient and controlled gene expression, and improve safety by preventing any escape of infectious viral particles outside the host plant. Compared with production systems based on transgenic plants, viral vectors are easier to manipulate and recombinant proteins can be produced not only very quickly but also in greater yields. In the last few years, a great deal of interest has been evinced in the development of plant viruses as vectors for the production of vaccines, either as whole polypeptides or epitopes displayed on the surface of chimeric viral particles. Quite a few viruses have been extensively developed for vaccine production, including tobacco mosaic virus, potato virus X and cowpea mosaic virus. Vaccine candidates have been produced against a range of human and animal diseases, and in many cases have shown immunogenic activity and protection in the face of disease challenge.
eBook - ePub- Charles Neal Stewart, Alisher Touraev, Vitaly Citovsky, Tzvi Tzfira, Charles Neal Stewart, Alisher Touraev, Vitaly Citovsky, Tzvi Tzfira(Authors)
- 2011(Publication Date)
- Wiley-Blackwell(Publisher)
E. coli , high cloning capacity, Gateway recombination sites, improved compatibility with the strains of choice, a wide pool of selectable markers, a high frequency of transformation, and so on. While classic vectors are still sufficient for many applications, improved vectors exhibit various user-friendly features. Vectors that are specifically designed to resolve certain regulatory issues, such as the removal of marker genes and reduction of transfer of the vector backbone, are also available. It is likely that the improvement of vectors will be continued as new technical demands arise in the plant science community. Although it is not difficult to find a vector that can somehow be used in a particular experiment, a further search for vectors better suited to the experimental purpose is often very useful.ReferencesAn G, Watson BD, Stachel S, Gordon MP, Nester EW (1985) New cloning vehicles for transformation of higher plants. The EMBO Journal 4, 277–284.Bevan M (1984) Binary Agrobacterium vectors for plant transformation. Nucleic Acids Research 12, 8711–8721.Chan PT, Ohmori H, Tomizawa J, Lebowitz J (1985) Nucleotide sequence and gene organization of ColE1 DNA. The Journal of Biological Chemistry 260, 8925–8935.Chang SS, Park SK, Kim BC, Kang BJ, Kim DU, Nam HG (1994) Stable genetic transformation of Arabidopsis thaliana by Agrobacterium inoculation in planta . The Plant Journal 5, 551–558.Chen H, Nelson RS, Sherwood JL (1994) Enhanced recovery of transformants of Agrobacterium tumefaciens after freeze-thaw transformation and drug selection. BioTechniques 16, 664–670.Christensen AH, Sharrock RA, Quail PH (1992) Maize polyubiquitin genes: structure, thermal perturbation of expression and transcript splicing, and promoter activity following transfer to protoplasts by electroporation. Plant Molecular Biology 18, 675–689.Conner A, Barrell P, Baldwin S, Lokerse A, Cooper P, Erasmuson A, Nap J-P, Jacobs J (2007) Intragenic vectors for gene transfer without foreign DNA. Euphytica
- Marc H.V. van Regenmortel, Brian W.J. Mahy(Authors)
- 2009(Publication Date)
- Academic Press(Publisher)
Plant Virus Vectors (Gene Expression Systems) 61 vectors that is valuable as an ‘amplifier’. Fortunately, replication is a relatively robust and species-independent mechanism. Two basic applications, namely rapid expression in small or large quantities and large-scale industrial pro-duction of proteins in plants, each require different design of the expression strategies. Vectors for Specific Application Areas Plant Virus Vectors as Research Tools Many different expression systems have been developed based on the backbones of entirely different viruses, and relying on different modifications of the core viral design. However, since the purpose of using such vectors is often rapid and high-throughput expression, and since only small (usually milligram) amounts of protein are usually required, many existing vectors do not contain the viral component(s) providing systemic movement. An important and limiting step for the use of viral vectors is infection of the plants with the viral replicons. Use of Agrobacterium to deliver a copy of the viral vector encoded on the T-DNA (‘agrodelivery’) provides an excellent solution since Agrobacterium is an extremely effi-cient vector. All the steps that are necessary for the conversion of the ‘agrodelivered’ T-DNA into a func-tional DNA or RNA replicon have been shown to occur in plants. ‘Agroinfection’ has been used for many years. It is also often much more efficient than mechanical inocu-lation using viral particles, and is definitely more efficient than using DNA or RNA as infectious molecules. In case of RNA viruses, agroinoculation also represents a very inexpensive alternative to in vitro transcription to convert the DNA vector into an infectious RNA. The use of agrodelivery for inoculation of RNA-viruses vectors also provides entirely new opportunities for vector engineering, since the vector is delivered to the plant cell as a DNA molecule, which can be manipulated prior to conversion into an RNA replicon.
- Khushboo Chaudhary(Author)
- 2019(Publication Date)
- Delve Publishing(Publisher)
These bacterial vectors will complement the YAC vectors for cloning segments larger than 100 kbp in length and offers some advantages over YAC system. These vectors have already been used for cloning large DNA segments from the bithorax gene of drosophila. 5.14. PLANT AND ANIMAL VIRUSES AS VECTORS A number of plants and animal viruses have also been used as vectors both for introducing foreign gene into cells and for gene amplification and expression in host cells. In the latter case, we may be interested only in getting increased quantity of the gene product and may not be interested in the integration of the foreign gene in the host genome. Some of the viruses that are commonly used as vectors will be described in this section. Tools of Genetic Engineering (Cloning Vectors) 141 Plant viruses (cauliflower mosaic virus or CaMV and germiniviruses) Cauliflower mosaic viruses, tobacco mosaic virus (TMV) And geminiviruses are three groups of viruses that have been used as vectors for cloning of DNA segments. CaMV infects particularly the members of Cruciferac and has a double stranded DNA molecule, 8kbp in size, whose sequence is now known. Following infection, the virus spreads systematically throughout the plant in a very high copy number reaching up to 105 virus particles per cell. These features make Ca MV a suitable vector for transformation of higher plants although there are instance of use of other viruses also as vectors leading to the production of transgenic plants. Geminiviruses comprise a group of single stranded DNA plant viruses causing important diseases in cassava, maize and other cereals. They replicate via double stranded DNA forms and have been subdivided into two groups, one infecting monocots and transmitted by leafhoppers and the other infecting dicots and transmitted by whitefly. The dicot geminiviruses have two DNA segments in their genome, DNA A AND DNA B, both are essential for infection by mechanical inoculation.
eBook - PDF- H. John Newbury(Author)
- 2009(Publication Date)
- Wiley-Blackwell(Publisher)
In order successfully to transform a plant, certain criteria must be satisfied. These can vary widely depending on the application, but a useful set identified by Hansen and Wright (1999) include: • A target tissue that is competent for regeneration and/or propagation. • An efficient means of delivering DNA. • Agents to either select or identify transgenic tissues. • The ability to recover fertile transgenic plants at a reasonable frequency. • A simple, efficient, reproducible, genotype-independent and cost-effective process. • A short time-frame in culture to avoid somaclonal variation. In the course of product development, the structure and copy number of transgenes along with their stability must also be established, and this can have a bearing upon the method chosen for transforming a crop species. In most situations the ideal trans-genic line would possess a single simple insertion event with no extraneous DNA from the plasmid vector employed to effect DNA transfer. In this context, the various PLANT MOLECULAR BREEDING 86 methods of transformation have both advantages and disadvantages. Techniques that appear to fulfil the criteria set out above include protoplast transformation, micro-projectile bombardment (also referred to as biolistics) and Agrobacterium -mediated transformation. Various additional methods for gene transfer to plants have been developed; some have specific applications but may not meet all the criteria for development of a successful transformation system. No single approach has yet to prove effective in all species and it is likely that a range of gene transfer technologies will continue to be developed and refined. The methods for introducing DNA into plant cells are conveniently divided into two types: direct, and indirect. Methods based on the use of Agrobacterium or viruses fall into the latter category, where a vector is used to transfer DNA into cells of the target plant.
Index pages curate the most relevant extracts from our library of academic textbooks. They’ve been created using an in-house natural language model (NLM), each adding context and meaning to key research topics.
